Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Bissett-Berman 9060 Salinity Temperature and Depth

The B-B 9060 STD measured salinity, temperature and depth and whose analogue output was in graphical form. The plots created were of salinity and temperature versus depth which had to be manually digitised.

RRS Discovery Cruise 26 STD Data Documentation

Introduction

Documentation for STD data collected on RRS Discovery Cruise 26 (April - May 1969) by the Department of Oceanography, University of Liverpool, Liverpool, U.K., under the direction of P. Hughes.

Instrumentation

The instrument used was the University of Liverpool Bissett Berman Salinity-Temperature-Depth system type 9006.

Sampling and Data Processing

The data output from each STD lowering and raising was automatically recorded in analogue form as plots of salinity and temperature against depth.In the near surface layers spiking due to the differing response times of the temperature and conductivity sensors created a problem in interpreting the salinity profiles. The salinity profiles recorded by the STD system were subject to spiking errors towards low salinity during lowering and towards high salinity during raising. A satisfactory method of eliminating the salinity errors was obtained by superimposing the analogue traces recorded during the lowering and the raising of the STD probe and manually bisecting the resulting envelopes of salinity and temperature. The derived profiles were then digitized at depth intervals of 3m down to a depth of 300m. Below 300m digitisation was on the basis of 2 values every 15m (i.e. 307m, 315m, 322m, 330m, 337m, etc.). Exceptions to this scheme are given below:

RRS Discovery Station No.

Digitisation scheme

6896

every 3m to 600m, every 15m thereafter

6898

2m, 5m, 7m, 10m, 12m, 15m, etc.

6905

every 15m to 600m, every 30m thereafter

6908 - 6912, 6962 - 6966

every 1m

6917, 6983, 6984, 6997

every 3m to 300m, every 15m thereafter

6930, 6947, 6958

every 6m to 600m, every 30m thereafter

6967

every 1m to 100m, every 3m from 100m to 300m, then 307m, 315m, 322m 330m 337m, etc.

6969, 6971, 6982, 6998

every 3m to 300m, then 307m, 315m, 322m, 330m, 337m, etc. until 750m, every 15m thereafter

6981

7m, 15m, 22m, 30m, 37m, etc.

The STD casts were usually to a depth of 500m - 750m, but stations 6905, 6917, 6930 and 6947 went to a depth of 1500m - 2000m. A Dahn buoy was laid at station 6970, in 746m of water, and the STD was lowered to 300m every 30 minutes over a period of 2 days whilst the ship maintained its position. Only the first downcast is included in this dataset. A similar exercise was carried out at station 6985, with lowerings to within 5m of the sea bed, but these data have not been included. The absolute accuracies of the temperature and salinity measurements were checked by comparison with a series of temperature measurements and salinity samples obtained with reversing thermometers and Niskin bottles over the course of the cruise.

Reference

RRS Discovery Cruise 26, 3 April - 9 May 1969. Physical and chemical study of the upwelling area off north-west Africa. National Institute of Oceanography Cruise Report No. 26. 6pp.